Conventionally, a fuel vapor purge device including a seal valve provided in an atmosphere passage connecting a fuel tank and the atmosphere. For example, a fuel vapor purge device described in Patent Document 1 (Japanese Patent No. 4144407) closes a seal valve to seal a fuel tank when an internal combustion engine is stopped, for example. Accordingly, fuel vapor in the fuel tank is prevented from being discharged.
The fuel vapor purge device of Patent Document 1 may require an electromagnetic drive portion for driving a valve element of the seal valve to open or close the seal valve. Therefore, a body of the seal valve may become large, and the fuel vapor purge device may become large. Moreover, manufacturing cost of the fuel vapor purge device may be increased. Additionally, the seal valve is provided between a canister and the fuel tank in the fuel vapor purge device of Patent Document 1. Hence, fuel vapor generated in the fuel tank may attach to the seal valve, and the attachment of fuel vapor to the seal valve may thereby cause operational malfunction of the seal valve.